Technological power starts with upgrading lenses

Chapter 265 Turbofan-30 test!

After making sure everyone entered the test control room, Kang Chi finally nodded to Yan Hui.

The first round of ground tests of the WS-30 engine has begun.

In this round of testing, the main purpose is to simulate the engine's operating conditions under ground conditions.

After completing the first round of testing, it will be moved to a special outdoor venue for a second round of testing in special climates and conditions such as rain, ice, high temperature, sand and dust, bird strikes, smoke swallowing, etc.

For example, in the water swallowing test, in order to simulate the working conditions of the engine under weather conditions such as water vapor, clouds, fog, rain, snow and hail, a special water spray device will be placed in front of the engine, and then when the engine is running, a short Several tons of water are sprayed out in just a few minutes, and the engine must not stall to be considered qualified.

However, this test method is usually only used for jet aircraft and engines. For tilt-rotor aircraft like Yinhe, especially electric aircraft, this kind of extreme simulation is not very useful...

What an electric aircraft tests is the balance of the fuselage during actual flight, and the motor does not stall. If it is fixed on a bench, apart from measuring the impact of foreign objects on the propeller, other tests are of little reference value.

After the second round, special high-altitude simulation test equipment will be used to conduct high-altitude bench testing. This high-altitude simulation bench is a 'wind tunnel' specially used to test aviation engines, and can simulate various aspects of the engine flying at high altitudes. environment, such as different air pressure, air flow speed, air flow angle, temperature, etc.

In this simulated environment, more complex tests such as thrust transients, intake distortion-induced surge, high-altitude thrust, fuel consumption, ignition within the flight envelope, and stable combustion can be performed.

However, high-altitude simulation platforms are more difficult to build than wind tunnels. There are currently only two in the country. The first SB101 took a full thirty years to build, which shows the preciousness of its resources.

Therefore, it is generally not possible to just build an aircraft engine and send it directly to the high-altitude bench. At least it must pass the initial ground simulation test without any problems before the third round of high-altitude bench testing can be carried out.

According to statistics, design only accounts for 10% of the development costs of an aircraft engine, manufacturing accounts for 40%, and testing accounts for a full 50%.

Although Kangchi is very confident in the engine he built, this link is essential, otherwise no one would dare to use his engine...

"All departments are in place, the first round of testing, and the cold operation begins."

As Kangchi issued the order, an engineer decisively pressed the button.

At this time, what was being simulated was just starting the engine, starting oil filling and other preparations. About two minutes later, after confirming that all the data was normal, Kang Chi continued: "Start the idle test."

"Start idle test, engine ignition!"

As the test engineer pressed the ignition button, the engine inside finally started running. Even though there was a wall, everyone could still hear a sharp engine sound, and the atmosphere gradually became heated.

The idle test mainly simulates the warm-up, ground taxiing, final approach and landing phases after the engine is started.

In this state, the engine is basically controlled at the lowest speed.

The wind tunnel also only blows air at the lowest power to maintain basic air circulation.

It is worth mentioning that the working time of the wind tunnel is usually not very long, because the working principle of the wind tunnel is to compress air into a can. Once the air is released, it is gone, and the air must be recompressed to continue the next round of testing. .

And how long it can be left depends entirely on how fast you want the wind to blow.

Based on the performance of the wind tunnel at Aoying Base, the wind blowing at Mach 10 can only last for 3 seconds, while the wind at Mach 1 can last for 30 seconds.

Like Huairou's JF-22, the wind blowing at Mach 33 only lasts 100-300ms.

After all, the speed of Mach 33 is too fast. At this speed, it can cross the Pacific Ocean in 14 minutes. If you want to build a wind tunnel that can blow Mach 33 in 14 minutes...

Basically impossible!

Think about how much air you need to store?

Hoarding air also costs money!

Many cars are sent to the wind tunnel for wind resistance testing. If the wind blows for a few hundred yards, they will shout money. They say it is worth a thousand taels of gold once the wind tunnel blows, not to mention the Mach wind blowing by the airplane...

However, the Turbofan 30 is not an engine designed for supersonic aircraft. It can blow up to Mach 1, which can greatly save the time and cost of the entire testing process.

"The idle test is completed, the blades run stably, the engine temperature is normal, and no special vibrations were found."

"Received, ready to take off state simulation."

After the slightly boring slow-speed phase, the next step is the take-off test that everyone is most looking forward to. In this phase, the power of the engine will be gradually increased until the designed maximum power.

"Simulation of takeoff state, power slowly increases for 5 seconds..."

As the test staff began to slowly push a throttle lever similar in shape to that in an airplane cockpit, the sound of the engine in the test room suddenly began to get louder and louder, and the wind tunnel airflow also slowly accelerated.

When it accelerated to Mach 0.2, everyone heard the sharp sound of the engine suddenly increase by a level. The thrust curve on the big screen that rose sharply was about to enter the valley and slow down. As a result, after this sharp sound, there was suddenly another Starting to rise sharply...

what's the situation?

When Dong Jun's eyes quickly moved from the data screen to the engine live screen, he was immediately confused.

I saw that the tail of this so-called 'high bypass ratio engine' actually sprayed out an obvious red flame tail!

This is……

Variable cycle afterburner? !

Are you kidding me?

At this moment, he finally believed that this engine, which was smaller than the Turbofan 20, was theoretically possible to explode with a thrust three times higher than the Turbofan 20...

Because this is simply a dimensionality reduction attack!

The turbofan engine after turning on the afterburner actually has no distinction between inner and outer ducts. It is more like a turbojet engine, at least in terms of space utilization, the performance of the entire engine is maximized.

However, afterburner technology is usually only used in small bypass ratio engines that pursue extreme performance.

No one has ever used this technology on a large bypass ratio engine...

It feels like installing a performance car's nitrogen accelerator in a truck or family car...

This is not a dimensionality reduction attack.

And this thing is not the same as a car equipped with a nitrogen accelerator. The afterburner is part of the engine, so it is a complete redesign of the engine. Both the design and manufacturing difficulty are completely different.

Even if a nitrogen accelerator is installed on a truck, one has to consider whether the truck's body strength, balance, and tires can withstand it, not to mention an aircraft engine that is a hundred times more complex.

So it's very possible that this is simply not achievable with existing materials.

"The takeoff simulation is over. The maximum thrust of the bench during takeoff is 49.52KN. Continue the 30S continuous maximum power state test!"

"491.3KN!?"

"It's amazing, it actually reaches 50 tons of thrust!"

"..."

Looking at the thrust curve on the screen, everyone suddenly became excited.

KN is a relatively professional unit of expression in the field of aviation power. If converted into kilogram force, which is easier for ordinary people to understand, 491.3 KN is equivalent to 50098 Kgf (1 kilonewton = 101.971621 kilogram force), which is exactly 50.09 tons of thrust.

Even the two chief ministers, who had always behaved calmly, couldn't help but feel a little moved after seeing this data.

Regardless of whether Kangchi has added the afterburner technology and whether there is any suspicion of cheating, this result alone has completely broken the current record of all Chinese aero engines.

However, although everyone was excited, because the test was still in progress, everyone quickly restrained their emotions and stared closely at the thrust curve chart.

After all, in the past engine tests, there were some cases where some engines achieved amazing results, but suddenly an accident occurred the next second, so that the prototype was directly scrapped...

However, in the subsequent thirty-second continuous maximum power test, the engine's thrust curve also remained very stable, which made everyone feel a little relieved.

"The continuous maximum power state test was completed. The engine operating status is normal, the temperature is normal, the gas pressure pulsation in the afterburner return zone is normal, and no oscillating combustion phenomenon was found."

Thirty seconds later, the engine power begins to slowly decrease, followed by relatively boring finishing steps such as idle, parking, and cooling.

"Mr. Kang, the first round of testing was successfully completed. This is specific data analysis."

Not long after the finishing steps, Yan Hui handed Kang Chi the data he had just printed out.

"Everyone rest for ten minutes and then prepare for the second round of testing."

"OK."

Although Kang Chi said to rest for ten minutes, everyone had no intention of resting at this moment and began to discuss the test intensely.

As the engine design director of the Yun-20, Chi Jinliang couldn't help but go directly to Kang Chi and asked: "How did you do this by using afterburner technology on the large ducted engine? "

"And the length of this engine doesn't even look like 7 meters... It doesn't look like an engine with an afterburner."

Dong Jun couldn't help but add: "Are you sure this is a high bypass ratio engine?"

Kang Chi smiled and pulled out a design drawing of the engine: "The bypass ratio is 6:1, it is definitely a large bypass engine."

"The length is less than seven meters. That's because I moved the afterburner forward to the inner tunnel combustion chamber area. To put it bluntly, this is a turbojet design with two combustion chambers."

The two were immediately stunned after hearing this.

Move the afterburner forward to the area of ​​the inner tunnel combustion chamber? !

Isn't this putting the connotation on the fire? !

"This...how many hours is the designed service life of your engine?"

"Twenty thousand."

"This is impossible!" Chi Jinliang immediately exclaimed, "Your Inner Dao will definitely not last a thousand, no...it will be scrapped after a hundred hours!"

Because of his excitement, he didn't even control his volume, and immediately attracted everyone's attention.

Faced with this question, Kang Chi just pulled out another pile of information without changing his expression: "How do you know you can't last a hundred hours? Why don't you take a look at this first?"

[A new structural ceramic material with high temperature resistance, high strength and corrosion resistance composed of Al203, ZrO3, C-BN, Si3N4, Sic and other materials——PG01]

After seeing this title, Chi Jinliang's expression suddenly froze, and then he quickly read it carefully, and then the hand holding the document began to tremble...

Density 1.06g/cm3,

Tensile strength 300kgf/mm2,

Fracture toughness reaches 600kgf/mm

Maximum withstand temperature 4600℃,

…

Looking at these data that completely crushed the existing aero-engine materials, some data even doubled, Chi Jinliang's mind suddenly went blank.

How can this be! ! ?

But……

The facts seem to be right in front of us.

Otherwise, how could it be possible to add an afterburner to an engine no longer than seven meters tall?

Without an afterburner, how could an engine with a casing diameter of only 4.4 meters possibly produce fifty tons of thrust?

So the most eye-catching thing about Kangchi’s engine is actually not the engine itself.

But this material completely breaks the bottleneck of engine development!

What the hell,

What kind of monster is it?

Chi Jinliang returned the information to Kang Chi blankly, then silently walked to the corner, found a chair and sat down.

At this moment, he just wants to be quiet...

Seeing that Chi Jinliang was so beaten by Kang Chi that he was almost autistic, Dong Jun couldn't help but feel powerless.

But soon, he thought of a question.

Fifty tons of thrust is achieved with the afterburner turned on.

Although the engine in this state has high thrust, it consumes very much fuel, so it cannot be turned on all the time.

Otherwise, the range will drop sharply and there will be no practical value.

It is precisely because of the problem of fuel consumption that turbojet engines have been basically eliminated since the fourth generation of fighters.

"If the afterburner is turned off, how much thrust can it have when cruising?"

The angle of my question is very tricky.

Kang Chi smiled slightly mysteriously and replied: "Don't worry, the test is not over yet."

Of course he knew what Dong Jun was thinking.

If the thrust after turning off the afterburner is not enough, the aircraft's cruising speed will be very slow. If you want to increase the cruising speed, you have to increase the engine power, which will also consume a lot of fuel.

Therefore, changing from four engines to two may turn it into a small horse-drawn cart, and the range may actually become lower.

Although the maximum thrust increased in this way can also increase the load capacity and reduce the take-off distance, the limitations are also very strong.

At this time, the variable bypass ratio can play a huge role.

Seeing that Kang Chi was showing off, Dong Jun suppressed his inner curiosity and quietly waited for the next test.

About an hour later, the preparations for the second test were finally completed.

"All departments are in place and ready to start the eighth project of the first round of testing, the variable duct cruise test!"

Change...change into a culvert! ?

Dong Jun's eyes suddenly widened.

In the discussion just now, Chief Shen and Chief Lu were just standing by, listening quietly to their technical discussions. They could not intervene on such technical issues, and there was no need for them to intervene.

Anyway, you can get a general idea of ​​the situation through the few words you can understand.

But after hearing the name of this round of tests reported by Kang Chi, the two bosses could no longer remain calm.

"Change into duct... your engine...can still change into duct!!?"

Although Chief Shen was trying his best to remain calm, his trembling voice could not conceal the excitement and shock in his heart at this time.

For a long time, variable duct technology has only existed in theory. Currently, no one in the world has been heard of who can build such an engine.

But Kangchi suddenly told them: Our next test is to change the duct.

Is this surprise too big?

Or was it just a joke?

"Yes, the WS-30 is actually a variable bypass engine with a bypass ratio of 6-10!"